The present invention relates to articles comprising bodies of polymeric material. Specifically, the present invention relates to bodies of elastic polymeric material.
Bodies of polymeric material and in particular of olefinic polymers are well known in the art and enjoy widespread usage throughout the industry. Typical areas of application of such body of polymeric material include for example medical applications, hygienic applications, automotive parts, sporting goods, and the like.
Conventional bodies of polymeric materials can be subdivided into rigid bodies and elastic bodies. Bodies made from commonly used polyolefins such as PP, PE, PS, PIB have a number of useful properties. They are bio-compatible and food compatible, chemically stable, inert, non toxic materials. However, most of them are rigid and have poor mechanical properties including insufficient stretchability/elasticity and the like.
Several approaches have been proposed in the prior art to render such bodies of polymeric material elastic. The most commonly used approach is based on changing the chemical structure of the polymer by introducing hinged joints/moieties into the main chain of the polymer. These hinges provide more flexibility to the polymeric backbone preventing crystallization of polymer, lowering the glass transition temperature (Tg) and improving the elasticity of the resulting material. Usually, the hinge groups contain heteroatoms providing flexibility such as oxygen, nitrogen or chlorine placed into the main chain or into bulky side groups. Another approach is mastication of the polymer by blending with special plasticizing agents. Both approaches, however, require heteroatoms to be introduced into the molecule or into the bulk of the body.
The third approach proposed in the prior art to provide elastic properties to such bodies of polymeric material, which is more close to the present invention, is to exploit the formation of hetero-phases which reinforce the bulk material by forming a physical net. To do this the block-co-polymerization of two or more different monomers has been used leading to polymeric backbones comprising blocks with different Tg. This results in micro-phase separation in the bulk with formation of reinforcing crystalline domains of one co-polymer linked with each other by flexible chains of the second co-polymer.
In essence, conventional bodies of polymeric material however carry a wide variety of inherent disadvantages including but not being limited to insufficient strength/tear resistance, insufficient stretchability/elasticity, not being bio-compatible, not being food compatible, comprising heteroatoms such as chlorine and hence leading to toxic residues when burnt, and the like.
It is a further object of the present invention to provide articles which comprise bodies of polymeric material which overcome the disadvantages of the prior art bodies of polymeric material.
It is a further object of the present invention to provide a method for manufacturing bodies of polymeric material suitable for the article of the present invention.
It is a further object of the present invention to provide a method processing a body of polymeric material suitable for the article of the present invention.
The present invention provides an article comprising a first element and a second element separated from and joined to said first element, said first element being a body of polymeric material. The article of the present invention is characterized in that said body of polymeric material comprises linear isotactic polymers having a structure of one or several C2 to C20 olefins, the isotacticity of said polymers, due to a statistic distribution of stereoscopic errors in the polymer chain, being within the range of 25% to 60% of [mmmm] pentad concentration with the proviso that an arbitrary or rather regular sequence of isotactic and atactic blocks is excluded, the polymer having a mean molecular weight Mw within the range of from 100000 to 800000 g/mol and a glass temperature Tg of between xe2x88x9250 to +30xc2x0 C.
The present invention further provides a method for manufacturing a body from polymeric material comprising a step of processing said polymeric material selected from the group of to injection molding, extrusion blow molding, extrusion, casting, solution sedimentation, and combinations thereof. The method of the present invention is characterized in that said polymeric material comprises linear or branched isotactic polymers having a structure of one or several C2 to C20 olefins, the isotacticity of said polymers, due to a statistic distribution of stereoscopic errors in the polymer chain, being within the range of 25% to 60% of [mmmm] pentad concentration with the proviso that an arbitrary or rather regular sequence of isotactic and atactic blocks is excluded, the polymer having a mean molecular weight Mw within the range of from 100000 to 800000 g/mol and a glass temperature Tg of between xe2x88x9250 to +30xc2x0 C.
The present invention further provides a method for processing a body of polymeric material comprising a step selected from the group of thermoforming, laser forming, carving, and combinations thereof. The method of the present invention is characterized in that said body of polymeric material comprises a linear or branched isotactic polymers having a structure of one or several C2 to C20 olefins, the isotacticity of said polymers, due to a statistic distribution of stereoscopic errors in the polymer chain, being within the range of 25% to 60% of [mmmm] pentad concentration with the proviso that an arbitrary or rather regular sequence of isotactic and atactic blocks is excluded, the polymer having a mean molecular weight Mw within the range of from 100000 to 800000 g/mol and a glass temperature Tg of between xe2x88x9250 to +30xc2x0 C.